1. Field of the Invention
The present invention relates to a moving image recording apparatus, a moving image recording method, and a program. In particular, it relates to recording of moving image data in a write-once recording medium whose files are managed by a file allocation table (FAT) file system.
2. Description of the Related Art
Conventionally, a FAT file system is used to manage files in small electronic devices such as digital cameras. In the initial region of the FAT file system, a management region is set. The management region includes data management information, such as a master boot record, a boot sector, a FAT, and root directory entries. A data region is set after the management region. In the management region, basic information about the FAT file system is written, such as a data region size and a cluster size representing a logical minimum recording unit of the storage device. In the data region, data is stored.
Examples of such recording medium (which may be simply referred to as “medium,” as needed) using the FAT file system include a general medium in which data is rewritable and a write-once medium in which data can be written only once. Generally, when moving image data is recorded in a medium using the FAT file system, the FAT once written in the medium is modified, and next, data is additionally recorded. However, when moving image data is recorded in a write-once medium, since rewriting is not possible, moving image data cannot be recorded by conventional methods.
According to a recording control device discussed in Japanese Patent Application Laid-Open No. 2010-020576, when moving image data is recorded in a write-once medium, a file is created in several batches. More specifically, 1 cluster is added to 3 clusters used as a writing unit to secure 4 clusters (clusters 4 to 7), and read moving image data of 3 clusters are sequentially allocated to the secured clusters 4 to 6. No data is recorded in the last cluster. If other moving image data needs to be recorded, a process similar to the first process is repeated to continue recording.
When recording the moving image data in a medium, users may wish to know time in which the moving image data is recordable. However, the recording control device discussed in Japanese Patent Application Laid-Open No. 2010-020576 does not include a configuration to calculate the moving image recordable time. Thus, the users cannot recognize the moving image recordable time. In addition, the recording control device discussed in Japanese Patent Application Laid-Open No. 2010-020576 repeats a process of recording and writing the secured FAT in a medium a number of times. Thus, it is difficult to increase the recording speed of moving image data. If a process of calculating the moving image recordable time is added to the recording control device discussed in Japanese Patent Application Laid-Open No. 2010-020576, processing load will be increased further.
In addition, a moving image recording time calculation device discussed in Japanese Patent Application Laid-Open No. 2004-228826 only displays the remaining capacity of a medium. The device does not calculate the moving image recordable time when a write-once medium is attached. Namely, when the device records moving image data in a write-once medium, there are cases where the moving image recordable time calculated based on the FAT read out to a memory is shorter than the moving image recordable time calculated based on free space of the medium. Thus, in the moving image recording time calculation device discussed in Japanese Patent Application Laid-Open No. 2004-228826, users cannot recognize that the moving image recordable time is actually shorter when recording moving image data in a write-once medium.